CHARACTERIZATION OF LIMESTONE QUARRIES FOR THE PREDICTION OF PENETRATION RATE IN EWEKORO AND SAGAMU, OGUN STATE, NIGERIA

Abstract

The research analyzed the characterization of limestone in selected quarries in Ogun State for the prediction of penetration rate. The research was conducted using the field data and rock samples collected from the two locations, that is, Sagamu (latitude 60451N and longitude 30351E) and Ewekoro (latitude 60351N and longitude 3o121E). The field data were used for the determination of penetration rate while rock samples were used for the laboratory analysis. The result of modal analysis from the thin section shows that Sagamu has the mineralogical composition of 79.5% calcite, 13.5% quartz and 7.0% opaque while Ewekoro has 77.5% calcite, 17.0% quartz and 5.5% opaque. The average density of Sagamu as determined in the laboratory is 2.68g/cm3 while Ewekoro has an average density of 2.71g/cm3. The average porosity of Sagamu is 3.08% while Ewekoro has an average porosity of 3.06%. The rebound hardness result shows that Sagamu has an average value of 32.3 while Ewekoro rebound hardness value has an average of 35.1. The result of uniaxial compressive strength as estimated from the correlation chart between average density and Schmidt hardness shows that Sagamu has average strength of 61.8 MPa while Ewekoro has an average uniaxial compressive strength of 72.4 MPa. The point load strength index for Sagamu has an average value of 1.6 MPa while Ewekoro has an average value of 1.8 MPa. The tensile strength as estimated from point load strength index for Sagamu has an average value of 2.5 MPa while Ewekoro has an average value of 2.7 MPa. The penetration rate as determined from field data shows that Sagamu has an average penetration rate of 0.7 m/min and Ewekoro has an average penetration rate of 1 m/min. The statistical model was developed using Statistical Package for Social Sciences (SPSS) software and the result shows that there is a strong correlation between penetration rate and porosity, rebound hardness value and density. The result also shows that the porosity, rebound hardness value and uniaxial compressive strength have negative influence on penetration rate while density has positive influence on penetration rate.